// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/browser/startup_task_runner.h"

#include "base/bind.h"
#include "base/location.h"
#include "base/message_loop/message_loop.h"

namespace content {

StartupTaskRunner::StartupTaskRunner(
    base::Callback<void(int)> const startup_complete_callback,
    scoped_refptr<base::SingleThreadTaskRunner> proxy)
    : startup_complete_callback_(startup_complete_callback)
    , proxy_(proxy)
{
}

StartupTaskRunner::~StartupTaskRunner() { }

void StartupTaskRunner::AddTask(StartupTask& callback)
{
    task_list_.push_back(callback);
}

void StartupTaskRunner::StartRunningTasksAsync()
{
    DCHECK(proxy_.get());
    int result = 0;
    if (task_list_.empty()) {
        if (!startup_complete_callback_.is_null()) {
            startup_complete_callback_.Run(result);
            // Clear the callback to prevent it being called a second time
            startup_complete_callback_.Reset();
        }
    } else {
        const base::Closure next_task = base::Bind(&StartupTaskRunner::WrappedTask, base::Unretained(this));
        proxy_->PostNonNestableTask(FROM_HERE, next_task);
    }
}

void StartupTaskRunner::RunAllTasksNow()
{
    int result = 0;
    for (std::list<StartupTask>::iterator it = task_list_.begin();
         it != task_list_.end();
         it++) {
        result = it->Run();
        if (result > 0)
            break;
    }
    task_list_.clear();
    if (!startup_complete_callback_.is_null()) {
        startup_complete_callback_.Run(result);
        // Clear the callback to prevent it being called a second time
        startup_complete_callback_.Reset();
    }
}

void StartupTaskRunner::WrappedTask()
{
    if (task_list_.empty()) {
        // This will happen if the remaining tasks have been run synchronously since
        // the WrappedTask was created. Any callback will already have been called,
        // so there is nothing to do
        return;
    }
    int result = task_list_.front().Run();
    task_list_.pop_front();
    if (result > 0) {
        // Stop now and throw away the remaining tasks
        task_list_.clear();
    }
    if (task_list_.empty()) {
        if (!startup_complete_callback_.is_null()) {
            startup_complete_callback_.Run(result);
            // Clear the callback to prevent it being called a second time
            startup_complete_callback_.Reset();
        }
    } else {
        const base::Closure next_task = base::Bind(&StartupTaskRunner::WrappedTask, base::Unretained(this));
        proxy_->PostNonNestableTask(FROM_HERE, next_task);
    }
}

} // namespace content
